textproduct: Rapid City

KEY MESSAGES

-Elevated to critical fire weather conditions into Monday

-Strong cold front will bring breezy weather Monday and much cooler conditions for Tuesday

-Mainly dry this week

-Smoke from western wildfires expected tonight into Monday

DISCUSSION

(This Afternoon Through Saturday) Issued at 1104 AM MDT Sun Aug 2 2026

Western CONUS upper ridge will retrograde and flatten as a strong upper trough moves across interior Canada. A strong cold front will cross the region early Monday with cooler temps for mid week. However, the ridge will rebuild and support hot weather by the end of the week, with 90s returning. Lee side trough settling into the FA with winds shifting NW across NW SD and northeast WY. Breezy southerly winds will persist ahead of this trough, esp SW through scentral SD, continuing through tonight as the LLJ intensifies. Dry weather expected through most of Monday, with the next chance of rain in the FA expected Monday night into Tuesday morning. Main cold front will move through Monday morning with winds gusting over 30-40 mph through much of the day on the SD Plains. A batch of thick low level smoke from OR/WA wildfires is expected to push through the region behind the front tonight into Monday per HRRR/RAP forecasts. This may impact visibility for a period, esp Monday morning. Conds will improve Monday evening as the ll trajectories indicate a more northerly origin to the incoming airmass. There is a very small chance that a shower or storm could develop along the cold front in scentral SD late Monday afternoon, but left things dry given expected strong capping. Still could see a few showers and TS across the southern third late Monday night as the jet entrance region will overlap with a weak impulse passing to the south of the FA, supporting elevated convection. The best chance will be in scentral SD where the better elevated moisture and forcing will be. Temps will fall into the 40s and 50s Monday night with a few 30s expected in portions of the higher Black Hills. Highs Tues will be 10 to 15 degrees below seasonal norms mainly in the 70s, with 60s in the Black Hills. Western ridge will gradually rebuild behind the deep upper low slowly pushing east across interior Canada. This will support a warm up with increasing LL moisture as SE return flow ensues. Expect highs to be back in the 90s by Thur, with triple digits possible by Sat on the SD Plains. Increasing LL moisture will support isolated TS chances by Wed as weak impulses will advect through the region in NW flow. Flow looks to become a little more active into the following week (after the 10th) as some of the longer range models indicate a stalled frontal boundary over the region with faster flow aloft, combined with appreciable LL moisture.

AVIATION

(For the 18Z TAFS Through 18Z Monday) Issued At 1123 AM MDT Sun Aug 2 2026

VFR conditions are expected to continue across the terminals through the valid TAF period. Main aviation concerns will be frontal boundary moving through the terminals, between 09-11z bringing a wind shift from the S to NW and turn breezy with sustained winds between 15-20 knots and gust between 25-30 knots. In addition to the winds FU will impact the terminals bringing a slight reduction to slantwise visibility.

FIRE WEATHER

Issued At 1104 AM MDT Sun Aug 2 2026

A strong cold front will move into the region Monday. Ahead of the front breezy southerly winds can be expected tonight across south central SD. North winds will increase after 9 AM Monday gusting to over 30-40 mph through most of the day on the SD Plains. Relative humidity will drop into upper teens to mid 20s Monday afternoon. Although RH's will be marginal, the gusty winds combined with cured fuels will support critical fire weather conditions on most of the SD Plains and portions of the northeast WY Plains. A red flag warning has been issued. Winds will gradually diminish Monday evening with a chance for showers and thunderstorms through the night from the Black Hills south east, best chance across south central SD. Much cooler weather can be expected Tuesday, before hot and mainly dry weather returns later in the week.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning from 11 AM to 8 PM MDT Monday for SDZ322>333. Heat Advisory until 8 PM MDT this evening for SDZ013-014-026-027- 030>032-041>044-072>077. WY...Red Flag Warning from 11 AM to 8 PM MDT Monday for WYZ317.